Nearly 87% of adults report drinking alcohol at some point in their life and over 70% report drinking in the past year. More importantly, nearly 25% report past month binge drinking, close to 7% report heavy drinking, and 29 million people report driving under the influence of alcohol. While significant numbers of adults report past month risky drinking, 90% of those who drink too much do not meet the criteria for alcohol dependence. Alcohol misuse contributes significantly to myriad health and safety risks, and annually costs the United States $223.5 billion, with the vast majority of those costs borne by employers. Several Internet-based interventions designed to address excessive drinking have now been developed, and a variety of studies have demonstrated the efficacy of these approaches. However, because virtually all of the online alcohol misuse prevention programs developed to date highlight alcohol misuse at the outset, their reach is limited to the self-identified problem drinkers and fail to provide the larger mainstream of drinking adults with prevention messages and materials. These mainstream drinkers are unlikely to engage with a program focusing solely on alcohol misuse because of the significant stigma associated with alcohol abuse disorder. Building on ISA's extensive experience in the development and test of substance misuse prevention and health promotion interventions (including previously developed and tested video and web-based interventions which circumvent the stigma associated with substance misuse by imbedding the intervention into widely accepted health promotion), the proposed project will develop and test an innovative mobile web-based alcohol misuse prevention program imbedded within a larger web-based workplace wellness program, suitable for access on virtually any smartphone (IOS or Android). The wellness program will include stress management, exercise, nutrition/weight management, and alcohol misuse prevention. Upon entering the wellness program, users will complete an assessment of their health practices and status (including drinking practices), which will tailor the wellness program to their particular needs and preferences. Phase I will involve focus groups and the development, usability and feasibility testing of the prototype, along with specific milestones tha must be met before moving to Phase II. Phase II will involve the full development of the mobile website and tools designed for users to access in-the-moment to help them change their behavior, followed by a randomized controlled trial with working adults to test the program effectiveness. Chestnut Global Partners, an international company specializing in workplace wellness and substance abuse prevention, has enthusiastically agreed to collaborate on the project to recruit workplaces and employees from among their client companies and to work with ISA's Center for Workforce Health to market the completed program.